There is known a power installation, comprising two hydro-units and a supporting carcass, wherein the first hydro-unit is mounted coaxially to the second hydro-unit. The units each includes a rotor furnished with blades, wherein the blades are so orientated that provide rotation of the rotors in the opposite directions, not rotatable cases facing each other are fixed to a cross-shaped frame coupled to the ends of arms with the carcass located outside of the rotation trajectory of the blades, which carcass is supported underneath by a floatable platform kept in floating position at a predetermined depth, mounted to bottom anchors by means of elastic straps (Patent of Russian Federation 2052658 issued 20 Jan. 1996).
Shortcomings of this solution are low efficiency and impossibility to use the installation effectively enough in a wide range of speed of water currents.
The most close prior art solution to the invention in terms of technological essence and achievable result is a power installation for conversion of water streams comprising an orthogonal balanced hydro-unit including at least two bladed rotors with vertical axed of rotation, mounted below the water level one above the other, capable of rotation in the opposite directions, an electro-generator and a system of fastening to a base structure (Patent of Russian Federation 2242634, issued 20 Dec. 2004).
The aforesaid hydro-unit comprises two annular rotors having blades so arranged relatively to the water stream that the rotors are rotatable in the opposite directions around a vertical axe, linear (arc) electro-generators with electric current takeoff means, a base represented in the form of a central pylon attached to the bottom of a water reservoir, a suspension members that transfer radial loads from the blades to the central pylon. The design of such unit allows considerably reducing reactive loads. However the presence of the electric current takeoff means reduces reliability of the unit, and the suspension system offers hydro-dynamical resistance to the stream that reduces power efficiency of the unit.
The present invention is therefore directed to solving a problem of decreasing both aero- and hydro-resistance of a power installation and reduction of losses of energy in support elements of the power unit, as well as combining the function of floating support with the function of support for an additional power source in the form of a wind power unit. The proposed invention allows increasing reliability and overall economic efficiency of the power installation.